1. Field of the Invention
The present invention relates to an injection valve for injecting a medium, e.g., for injecting fuel into a combustion chamber, which injection process may be developed as a port injection or as a direct injection.
2. Description of the Related Art
The related art includes known injection valves for the injection of Otto fuel. They have a valve needle which is moved against a closing spring by an actuator, e.g., an electromagnet or a piezo actuator, in such a way that a desired fuel quantity is selectively introduced directly into the combustion chamber. In the case at hand, an injection valve is examined in which the magnetic armature is decoupled from the valve needle. When the injection valve is opened, the magnetic armature is meant to rapidly detach from the lower stop (second stop) on the valve needle, to rapidly overcome the armature free travel, and to quickly open the valve when striking the upper (first) stop. If the energization of the valve is stopped, then the valve needle closes again. Once the valve needle seals the valve seat again, the magnetic armature continues its movement until it strikes the lower stop. The armature bounces off the lower stop multiple times before reattaining its idle position. The time until the magnet armature is reset to the idle position again is decisive for the ability of the valve to deliver injections in rapid succession and with high accuracy. A squish gap is usually developed at the lower stop, i.e., between the magnetic armature and the corresponding stop sleeve on the valve needle. The medium to be injected is squeezed into this squish gap, so that the magnetic armature is reset to the idle position in a damped and rapid manner during the closing. However, by damping the movement during the opening, the squish gap prevents a rapid opening. As a compromise, the squish gap must therefore be configured in such a way that the magnet armature opens the valve with sufficient speed and is reset to its idle position with sufficient speed as well.